Procedures are presently known for treatment of a variety of vascular conditions, including treatment of vascular obstructions and enlargements. For example, in a typical percutaneous transluminal coronary angioplasty (PTCA) procedure, a guide catheter is introduced into the cardiovascular system of a patient and advanced through the aorta until the distal end of the catheter is in the ostium of the designated coronary artery. Using fluoroscopy, a guidewire is then advanced through the guide catheter and across the site to be treated in the coronary artery. A balloon catheter is then advanced over the guidewire to the treatment site, and at which point the balloon is expanded to reopen the artery. To help prevent arterial closure, repair dissection, and/or prevent restenosis, a physician can implant an intravascular prosthesis, for example, a stent, inside the artery at the treatment site. Unfortunately, in some cases, the arterial obstruction is so extensive that the physician has difficulty advancing the various medical devices past the obstruction. Thus, there is, in general, a need to advance devices that have a cross-sectional profile that is as small as possible. Moreover, current balloon catheters can be described as having a hydraulic actuating mechanism. Because hydraulic systems are more efficient at larger dimensions, the present trend to downscale device sizes has created the need for actuators that efficiently function at very small diameters. Furthermore, in rare instances, the physician may have to withdraw a stent (or other prosthesis) that has tracked in an artery, during which time the edge of the stent may catch on a lesion or guiding catheter and be at risk for embolization.
In contrast to treating obstructions, other vascular procedures are used to treat vascular enlargements. For example, in one presently known method for the treatment of an aneurysm, the physician initially places a catheter into the mouth of the aneurysm. A coil is then inserted through the catheter and into the aneurysm. With some coils, for example, Guglilmi detachable coils (GDCs), if the physician does not like the coil's configuration, he or she can remove it and reposition it or choose another size coil. In the case of the GDC, the coil is a soft platinum coil that is soldered to a stainless steel delivery wire. When the coil is properly positioned within the aneurysm, a small current is applied to the delivery wire, dissolving the same at a position proximal to the platinum coil by means of electrolysis. Once electrolysis occurs, the delivery wire can be removed leaving the coil in place. Another coil can then be introduced. The process is continued until the aneurysm is densely packed with coils and no longer opacifies during diagnostic contrast injections. In general, the more tightly the coils are wound, the more densely the aneurysm is packed. There is a continuing need in the art for materials that will provide such coils.